The purpose of the present project is to develop a new type of RFID tagging system for tracking mice. It is based on the PharmaSeq laser light-activated microtransponder, also known as "p-Chip". Its major advantages are its small size (500 5m x 500 5m x 100 5m), monolithic (one part) design, inertness (silicon-based), ease of use and very low cost. No anesthetization of the mice is required. The system consists of the tag itself, the tag reader, and an injector for p-Chips. The p-Chips are rapidly implanted in a mouse's tail just under the skin. To identify the animal, the operator simply brings a reader to within the immediate proximity of the implanted p-Chip and the ID is acquired automatically and transmitted to the a computer. The software further associates the ID of a particular mouse with data related to its role in experimental procedures and/or breeding history. The main goals of the project are to: (1) make several improvements to the injector regarding the ease of use, and fabricate a larger number of units;(2) conduct animal studies including biocompatibility in immunocompetent as well as immunosuppressed strains of mice;(3) modify the existing p-Chip/ID reader system, including the digital board and software;and (4) redesign of p-Chip/receiver system to work at higher frequencies (315 MHz). The system will be thoroughly tested in-house and in collaboration with outside laboratories. Tagging with p-Chips will improve the reliability of tracking of experimental subjects by preventing costly errors including rework due do unreadable markings and lost labels. PUBLIC HEALTH RELEVANCE: Laboratory mice play a powerful role in basic research and a key role in mammalian genetic and biomedical research. They are universally accepted as the primary model for analyzing and understanding inherited human disorders. The new PharmaSeq system has the potential to greatly increase the use of RFID tags in laboratory mice, or even to lead to the general adoption of this new technology as a universal tagging system that can track animals from breeding through their entire useful lifetime.